bug#53018: 29.0.50; pgtk child frame borders wont show

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Akira Kyle <akira@akirakyle.com> writes:

> In GNU Emacs 29.0.50 (build 1, aarch64-unknown-linux-gnu, GTK+ Version 3.24.30, cairo version 1.16.0)
> Repository revision: ab5ee3e29e916d4009b301841e9780aad564a6a0
> Repository branch: master
> System Description: NixOS 22.05 (Quokka)
>
> Configured using:
>  'configure
>  --prefix=/nix/store/0fiqa453abl4c1c28g0baqs9s274s7ff-emacs-pgtkgcc-20220103.0
>  --disable-build-details --with-modules --with-x-toolkit=gtk3
>  --with-cairo --with-xwidgets --with-native-compilation --with-pgtk'
>
> Window manager is sway and (pgtk-backend-display-class) is
> "GdkWaylandDisplay"
>
> Running the following lisp in emacs -Q:
>
> (add-to-list 'load-path "~/path/to/posframe")
> (require 'posframe)
> (posframe-show " *my-posframe-buffer*"
>                  :string "This is a test"
>                  :position 1
>                  :border-width 30
>                  :border-color "red")
>
>
> The child frame border look like appears for a split second before
> disappearing and it isn't colored red but inherits the default
> background color.

Thanks, should be fixed now on master.  Please test.